I am making a UAV at the moment that is powered by an Arduino Uno, and I think it would be a great feature to have a UHF/VHF radio so I could send and receive aviation radio comms if I ever needed to inform other aircraft or air traffic control of my UAV's intentions. Can anyone recommend a good way to do this using Arduino?

It might also be worth noting that I will be using a WiShield 2.0 to send information to a 3G hotspot on the UAV, and this audio data would be sent and received that way. I would sample the radio at about 8kHz (to be consistent with standard sampling procedures on aircraft), and I imagine each sample would be a byte. This means I would have to process 8,000 bytes for thresholding before I sent it to the WiShield, do you think the Arduino is capable of this?

EDIT: I should probably add I would like the Arduino to be capable of changing the frequency being monitored and broadcasted, and if possible the squelch.

I do have a radio operators license (I am a private pilot), and even though I do not plan to fly the UAV in airspace with regular traffic I don't discount the fact that something could happen that would put the UAV off course and potentially into the airspace of other aircraft. I don't expect to use Voice Recognition either, I would like to transmit by my comms link to the UAV and interact personally with them if I ever needed to. It's more of a safety feature than anything.

I was thinking of using a Handheld UHF/VHF radio, stripping the battery out of it (which I imagine would be most of its weight), and initially connecting the speaker and microphone wires directly into the arduino. I should be able to carry the payload of a batteryless handheld.

I think you are confused. I don't want to use them to control all my UAV comms (that's reserved for 3G), all I want to do is be able to communicate with air traffic control or other air traffic if my UAV for some reason drifts off into airspace where it might cause a problem. So I would send and receive audio via 3G and use that on the onboard UHF/VHF radio.